Women who needed medicine, given glyburide or insulin
“The higher rate of the primary outcome in the glyburide group was mainly due to an increased rate of neonatal hypoglycemia.”
JAMA, 2018 · controlled trial · PMID 29715355
Episode check · Lifestyle and genes
Does a hard pregnancy predict your health later in life?
Insulin does the most for the newborn, the episode says. Ten studies split on it.
We checked five claims from a 122-minute episode on pregnancy against 69 studies. Two have strong support: folic acid and the spine, and the later heart and kidney risk after preeclampsia. Two lean in favor: that half of women with gestational diabetes get type 2 diabetes, and that exercise beats bed rest. The studies split on insulin for the newborn. Three found babies did better when the mother took metformin. The one study that favored insulin set it against a different pill. The chapters we did not check are in grey.
The source we checked
On YouTube as of Oct 12, 2026
“410 ‒ The biology of pregnancy: physiologic adaptation, childbirth, and long-term maternal health”
29 chapters · 5 claims checked against 69 studies · 24 chapters not checked yet · checked Oct 12, 2026 Watch on YouTube →
Why pregnancy is still a mystery
3:27 “I also was fascinated that we didn't understand anything like why do people go into labor?” Said on tape, not checked yet.
A stress test for the body
5:47 “it's a cardiovascular um stress test um because the plasma volume expands um so much um it is um a metabolic stress test because there's increased insulin um resistance” Said on tape, not checked yet.
Early hormones and morning sickness
9:19 “they found a signal that flagged the GDF-15 gene is uh really important in driving um who developed that condition.” Said on tape, not checked yet.
More blood, fewer red cells
12:04 “It starts immediately and kind of peaks at being total it it increased by 50% by 28 weeks.” Said on tape, not checked yet.
Folic acid and the baby's spine
Does folic acid before pregnancy prevent neural tube defects?
“there's good evidence that folic acid deficiency increases the risk of having a neural tube defect in the baby”
Kathryn Gray, a guest on this episode.
What 10 studies found
Strong consensus for
9 agree · 1 partly agree
Nine of ten studies found that folic acid lowers the risk of neural tube defects. These are birth defects of the spine and brain. The studies tested folic acid before and early in pregnancy, and they include the Cochrane reviews of trials. A pooled analysis put the risk at 0.38 times that of women who took none. One California study came after flour was fortified. It found pills added only a small benefit on top.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact wordsThe second trimester
24:31 “Um the metabolism might switch from like um being insulin sensitive to being more insulin resistance during that part of the pregnancy um given the growth of the placenta.” Said on tape, not checked yet.
Gestational diabetes and the baby
25:38 “I think it's meant to be adaptive, right? Providing enough fuel for the fetus to grow.” Said on tape, not checked yet.
Testing for gestational diabetes
28:46 “And actually data shows that when you diagnose it earlier it might not improve the outcomes at all.” Said on tape, not checked yet.
Treating gestational diabetes Lead finding
Is insulin better than metformin for the baby in gestational diabetes?
“but really insulin is most um effective and we have good safety data and it has the best um influence on improving the neonatal outcomes.”
Kathryn Gray, a guest on this episode.
What 10 studies found
Mixed
1 agree · 6 partly agree · 3 disagree
One of ten studies favored insulin, and only against glyburide, another diabetes pill. Three found babies did better when the mother took metformin. They had fewer stays in newborn intensive care and fewer bouts of low blood sugar. Six found insulin and metformin about even, or mixed. Several found insulin did better than glyburide.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact wordsDo half of women with gestational diabetes get type 2 diabetes?
“people will have type 2 diabetes and then they should also be surveiled for type 2 diabetes more closely following a pregnancy because they're at higher risk.”
Kathryn Gray, a guest on this episode.
What 10 studies found
Strong consensus for
10 agree
All ten studies found that women who had gestational diabetes face a much higher risk of type 2 diabetes later. A pooled analysis of more than a million women put the risk almost 10 times higher than for women without it.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact wordsCloser look
Look at which pill they tested
Trials that gave women metformin or insulin
“Risks of NICU admission and neonatal hypoglycemia were lower in the metformin group and reached a statistically significant level when compared with insulin (RR, 0.75; 95% CI, 0.64 to 0.87;”
J Diabetes Res, 2019 · pooled analysis · PMID 31781670
What preeclampsia is
39:01 “about 5% of pregnancies 5 to 7% depending on your patient population” Said on tape, not checked yet.
What goes wrong in the placenta
41:44 “If that is not adequate enough then the placenta has some degree of hypoxia” Said on tape, not checked yet.
Preeclampsia, delivery and the kidneys
Does preeclampsia raise heart and kidney disease risk later in life?
“have a longer term risk of kidney disease as well as cardiovascular disease.”
Kathryn Gray, a guest on this episode.
What 10 studies found
Strong consensus for
10 agree
All ten studies found that women who had preeclampsia face a higher risk of heart disease later in life. A pooled analysis put the risk of heart disease at 2.16 times that of other women. In Norway, deaths from heart disease ran 8.12 times higher after preeclampsia with an early birth.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact words“have a longer term risk of kidney disease as well as cardiovascular disease.”
What 10 studies found
Strong consensus for
9 agree · 1 partly agree
Nine of ten studies found a higher risk of kidney disease after preeclampsia. A pooled analysis put the risk of kidney failure at 4.90 times higher, after allowing for other causes. One study notes that obesity may explain part of the link.
Computed from 10 studies that test this point, each judged by two readers, in full. 7 more studies are waiting for a full read and do not count yet.
Every study and its exact wordsBlood pressure drugs in pregnancy
53:02 “We know for sure that they're not safe in pregnancy.” Said on tape, not checked yet.
What pregnancy shows about later health
Do half of women with gestational diabetes get type 2 diabetes?
“Yes. Um so 50% of patients who have”
Kathryn Gray, a guest on this episode.
What 10 studies found
Leaning for
3 agree · 7 partly agree
Three of ten studies found that about half or more got type 2 diabetes, after long follow-up. Seven found fewer. The largest pooled analysis found 17.0% overall. Another found about 9.22% in the first five years, and more with time. A large study in Ontario found 18.9% within 9 years.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact wordsCloser look
The share grows with time
How long a study followed women changes the answer. One pooled analysis put the share at 19.72% after 10 years and 29.36% after 20 years. A study in Finland found 50.4% after more than two decades.
Why C-sections went up
1:04:26 “Yeah, it's dramatically increased. you know, so we've we've gone from, you know, like 10% C-section rate” Said on tape, not checked yet.
Cords, stillbirth and what we can't explain
1:11:08 “Like a third of the time the baby comes out with a cord around the neck. It's very common. It usually doesn't cause a problem.” Said on tape, not checked yet.
Watching the placenta, and what starts labor
1:15:24 “we're only doing like Doppler monitoring on ultrasound when the baby is growth restricted.” Said on tape, not checked yet.
What labor feels like
1:18:18 “I think early contractions might kind of be like or you know Braxton Hicks like practice ones might be like having a really bad period like a really bad menstrual cramp.” Said on tape, not checked yet.
When the water breaks early
1:25:02 “the recommendation is to um give antibiotics at the time they um present and that's because it helps prolong latency.” Said on tape, not checked yet.
Birth, gut bacteria and breastfeeding
1:26:28 “Well, I I'm not saying that there's no helpful component of that, but I would say of all the things that help determine your health and your baby's health, that's probably not the thing to stress about.” Said on tape, not checked yet.
Exercise and sleep position
Is exercise during pregnancy better than bed rest?
“I think exercise is really important. The more data we get, the more we know like bed rest is bad. People do better when they exercise.”
Kathryn Gray, a guest on this episode.
What 10 studies found
Leaning for
1 agree · 8 partly agree · 1 disagree
Eight of ten studies partly agreed. Exercise helped the mother in some ways, such as less gestational diabetes or less weight gain. Birth weight and other outcomes for the baby did not change. One review agreed in full, and one trial in Brazil found no benefit.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact words“I think exercise is really important. The more data we get, the more we know like bed rest is bad. People do better when they exercise.”
What 6 studies found
Leaning for
2 agree · 4 partly agree
Two of six studies found harm. In one, early birth was more common among women told to limit their activity. Four found bed rest did no good but did not measure harm.
Computed from 6 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
Every study and its exact words1:32:49 “to lay completely flat on your back is probably not the best position” Said on tape, not checked yet.
Depression after birth
1:33:39 “in the first two weeks after delivery, there's just the most tremendous um uh collapse of the estrogen and progesterone levels” Said on tape, not checked yet.
Screening the baby's DNA from the mother's blood
1:37:15 “just a tube of the maternal blood um we can find fragments of the placental DNA and therefore um screen the pregnancy” Said on tape, not checked yet.
What DNA screening can and can't tell you
1:42:20 “So I think there's a big gap between what we can do from a technology standpoint and and our framework for how we um decide which things to screen for” Said on tape, not checked yet.
The hard days of the job
1:43:39 “Um those are those are really tough uh conversations.” Said on tape, not checked yet.
Midwives and the C-section backup
1:47:06 “of of anticipated vaginal deliveries about 20% end up going to C-section” Said on tape, not checked yet.
Labor pain
1:51:34 “for patients whose babies might be facing like sunny side up um that there seems to be like more pain in the in the back during labor.” Said on tape, not checked yet.
Mothers' deaths and health insurance in the US
1:54:29 “insurance access is a big deal.” Said on tape, not checked yet.
Research money for pregnancy
1:58:32 “it's been a neglected area in research. It's been an underfunded area of research” Said on tape, not checked yet.
How we checked this episode
We go through the episode chapter by chapter and pull out each claim. For every claim we can test, two readers read each study in full and mark whether it agrees, partly agrees or disagrees. A fixed rule turns those marks into the badge, the same rule Precis uses on every page. Nobody writes or edits a badge. Chapters we haven't checked are shown in grey, so you can see everything the episode said.
Every quote is 20 seconds or less and opens the episode at that second. This is not medical advice. Talk to your doctor before you change anything.