352 ‒ Female fertility: reproductive health, treating infertility & PCOS, and the IVF process

KEYPOINTS

• 01

  Women have a finite egg supply, and the real constraint with age is egg quality.

  Amato, a reproductive endocrinologist in Oregon, explains that egg numbers peak in the womb. There are about 2 million at birth and about 400,000 by first period, with most lost through atresia. Eggs stay arrested mid-meiosis until the days before ovulation. Errors in splitting the chromosome pairs at that stage, which become more likely as a woman ages, produce aneuploid eggs. Even with regular ovulation, many released eggs can't make a viable pregnancy.

• 02

  About 90% of first-trimester miscarriages come from chromosomal errors.

  Women shouldn't blame coffee or stress for an early loss—it's almost always a 'bad split.' One miscarriage isn't usually investigated. Two in a row warrants a workup at any age, even at 40, because a treatable cause such as a uterine abnormality could be missed.

• 03

  Infertility means a year of trying under 35, or six months over 35—and both partners get tested.

  Roughly a third of cases are female factor, a third male, and a third combined, so a semen analysis comes early. Lifetime infertility risk is about 1 in 6. Rising rates are partly explained by delayed childbearing, with possible roles for falling sperm counts and STIs. Irregular cycles or suspected PCOS justify seeing someone before the year is up.

• 04

  Untreated gonorrhoea and chlamydia can silently scar the fallopian tubes.

  Ascending infection—presenting as pelvic pain, fever and discharge, though not always noticed—damages tubes without affecting the eggs or uterus, so IVF still works. Scarred tubes also raise ectopic pregnancy risk, typically presenting at 6–8 weeks; a late rupture often means removing the tube. A dye X-ray of the uterus and tubes (HSG) checks they're open.

• 05

  PCOS affects about 6–8% of women and links irregular cycles, high androgens and insulin resistance.

  Not trying to conceive: birth control pills suppress LH-driven ovarian testosterone, raise SHBG and protect the uterine lining from overgrowth. Long gaps between periods can lead to hyperplasia and even cancer. Patients should be screened for diabetes, often with metformin. Many women are put on the pill without being told they have PCOS and its metabolic implications.

• 06

  For PCOS and fertility, letrozole for five days is first-line and works for most women.

  A head-to-head randomised trial found higher pregnancy rates than with clomiphene. If there's no period, a withdrawal bleed is induced with progesterone (5–10 mg medroxyprogesterone or 200 mg micronised for 7–10 days). Letrozole runs on cycle days 3–7, with an ultrasound around day 12. About 80% of PCOS patients conceive with ovulation induction plus IUI.

• 07

  Stop GLP-1 drugs at least two months before trying to conceive.

  They're very effective for weight loss in PCOS, but there are no pregnancy safety data. An 'Ozempic baby' registry hasn't shown birth defects so far, but numbers are small.

• 08

  IUI success depends heavily on age.

  With oral drugs, per-cycle rates are about 20–25% in the 20s, 10–15% over 35 and 1–5% over 40. Multiples risk is about 5–8% with oral drugs versus 25–35% with injectables. That's why injectables with IUI—the source of tabloid 'octuplet' stories—have largely been dropped in favour of IVF.

• 09

  IVF is a funnel, and a normal embryo implants about 70–75% of the time.

  A typical sequence: about 10 eggs retrieved, about 70% fertilise, about half reach blastocyst by day 5–6, and genetic testing (5–6 trophectoderm cells) removes more. Single-embryo transfer is the norm because twins raise risks of preeclampsia, haemorrhage, C-section and prematurity. Donor eggs give about 70–75% success, versus 10–20% per cycle for over-40s using their own untested embryos.

• 10

  The lab matters as much as the doctor.

  Amato says success depends more on embryologists than physicians. Training is mostly a 4–5-year apprenticeship, and there's a national shortage. Choose clinics using SART.org clinic-specific success data (about a two-year lag) and volume—at least 100 cycles a year. Ask how genetic testing is offered. Avoid clinics that push add-ons on everyone or where you rarely see the doctor. A cycle costs about $20,000; 24 states mandate some fertility coverage, about 15 including IVF.